At the appointment of Aaron and his sons shall be all the service of the sons of the Gershonites, in all their burdens, and in all their service: and ye shall appoint unto them in charge all their burdens.

Moreover David and the captains of the host separated to the service of the sons of Asaph, and of Heman, and of Jeduthun, who should prophesy with harps, with psalteries, and with cymbals: and the number of the workmen according to their service was:

Because their office was to wait on the sons of Aaron for the service of the house of the LORD, in the courts, and in the chambers, and in the purifying of all holy things, and the work of the service of the house of God;

These are they that were numbered of the families of the sons of Gershon, of all that might do service in the tabernacle of the congregation, whom Moses and Aaron did number according to the commandment of the LORD.

And after that went the Levites in to do their service in the tabernacle of the congregation before Aaron, and before his sons: as the LORD had commanded Moses concerning the Levites, so did they unto them.

And that they should keep the charge of the tabernacle of the congregation, and the charge of the holy place, and the charge of the sons of Aaron their brethren, in the service of the house of the LORD.

And the singers the sons of Asaph were in their place, according to the commandment of David, and Asaph, and Heman, and Jeduthun the king's seer; and the porters waited at every gate; they might not depart from their service; for their brethren the Levites prepared for them.